One of the terrific new features in Outlook 2007 is the ability to preview e-mail attachments without having to open them up in their corresponding application.  (For those of us old school guys, we've always been able to program this feature using OLE.)  Unfortunately when you look for some to add to Outlook, low and behold, there's none of them out there.

So, I guess it's up to use developers to do the dirty work and create some.

Here's a great tutorial on how to do this.

http://msdn.microsoft.com/msdnmag/issues/07/01/PreviewHandlers/default.aspx